Car suddenly slamming on brakes while auto pilot

Car suddenly slamming on brakes while auto pilot

This has happen to me 3 times over the course of 30 days (2800 miles) more than 2/3 of that AP.

Today: while driving about 55mph, car slam the brakes with no one in front. When i noticed the car was about 30. I floored the pedal to avoid an accident, looked back and luckily no one behind me. The car in front of me had to be atleast 150-200 ft.

2nd time: was at 70mph. Car slammed on brakes for no reason, or so I thought. 2 secs later, i noticed the car in front of the car in front of me swirled off the road to avoid hitting the third car. This incident happened at 6 AM so probably saved my life. I’m not sure how the car detected that far, with interaction of 3 cars in front of me.

First time: auto pilot around 75 mph, car slowed down to 50 on a small turn, wasnt sure why, resume the trip and took over from AP.

The today incident shooked me up, I do admit I was half of sleep.

gwolnik | 8 maggio 2018

Here is a video of a Tesla avoiding an accident 2 cars ahead of it:

dkabq | 8 maggio 2018

This is an older compilation of autopilot alerting or avoiding accidents, always found interesting:

gwolnik | 8 maggio 2018

I'm still puzzled why that Model X ran right into the barrier in Mtn. View. By the way, I drove past that accident going northbound (the other way) about an hour after it happened. I looked at the car as I passed and didn't even recognize it as a Tesla. All lanes were closed and the southbound backup went for miles. I turned on the radio traffic reports and they said it was an electric car and engineers from the nearby factory were coming out to help remove the batteries, so even without saying it was Tesla, I knew it was.

Coastal Cruiser. | 8 maggio 2018

Ok, the first rollover crash in the first link freaked me out pretty good. I pray that videos like this are being shown in High School Driver Ed classes. Exclamation point.

Dsmtesla | 8 maggio 2018

MIne does this all the time... For example if im in AP and a car turns in front of me (it can literally be 200ft in front of me) it will slow down as if its right in front of me, even though its cleared the entire intersection already... Very stupid

lilbean | 8 maggio 2018

Mine does this too. :(

lilbean | 8 maggio 2018

It also does this on TACC.

ebmcs03 | 8 maggio 2018
john | 8 maggio 2018

I have had it happen with nothing in front of me for a long way and also from the shadow of an overpass. On overpass shadows it is not consistent so you can never be sure whether it will react or not. The other times appear to be random events. It would help us identify the issues if whenever the car applies the brakes suddenly if follows up with a display message such as potential collision with_____ xx feet ahead or to the left or right side, etc. Maybe we could then determine what is triggering the behavior and report it to Tesla.

ebmcs03 | 8 maggio 2018

Turn on your hazard at that moment and tell tesla to Paul the logs at that time and see what triggered the sudden braking.

wiboater4 | 9 maggio 2018

smtesla | May 8, 2018
MIne does this all the time... For example if im in AP and a car turns in front of me (it can literally be 200ft in front of me) it will slow down as if its right in front of me, even though its cleared the entire intersection already... Very stupid

I'd rather have it do that for now to be safe than have a collision.

lilbean | 9 maggio 2018

This could actually cause an accident. The car could be rear-ended when it unnecessarily slams on the brake.

colinrego | 9 maggio 2018

@ebmcs03 That sounds like a good idea.

mos6507 | 9 maggio 2018

"The car could be rear-ended when it unnecessarily slams on the brake."

This is why autopilot should use the rear-facing camera. If it doesn't know what's behind it then it will feel like it can jam on the brakes anytime it likes.

Also, the recent story about the Uber vehicle having detected the pedestrian and "deciding" not to stop is somewhat related. We're dealing with a simulated nervous system, a fight or flight syndrome, so to speak. The same way a jittery person can be easily startled by a false-alarm, the autopilot can too if it doesn't have enough time to think about what it's sensing and how this or that course of action may have downstream consequences.

wiboater4 | 9 maggio 2018

So how fast does a computer think compared to a human? Think about that . Also keep in mind this stuff is still being improved. The guy following you is supposed to leave enough distance to stop if the car ahead of him has to stop for any reason. Yeah, I know nobody does that but you should.

Iwantmy3 | 9 maggio 2018

This seems like a common issue with detecting emergency braking situations. I have the same issue in my Ford Explorer. The emergency brake lights often come on when a car is turning on front of me even though I can see that they will easily clear my path before I get there. Of course, I as a driver am making the decision that that car on front of me will not suddenly stop before clearing my path. That isn't necessarily the safest assumption even if it seems certain.

When programming the car for those situations, the programmer would need to identify if the car is clearing the path and when the path would be clear. However, this would require knowledge of what the path of that other car is and what might cause it to stop for no apparent reason. It would seem that the programmers in this case have taken the less risky approach and assumed that the car will not clear the path until it has fully cleared the path. This will likely cause a number of annoying false stops. The issue will be much worse for driving in non-highway situations in the future.

slasher0016 | 9 maggio 2018

While I haven't had this experience, I have had it freak out and think someone was in the other lane when trying to do an auto lane change and swerve back when no one's there. One current weak point with EAP is lane recognition on non-highways (yes I know, you're supposed to only use on highways.) If you are following someone with EAP on, and they switch lanes to turn left or right, EAP slows down for a really long time until it figures out that car is in another lane.

laovision | 14 maggio 2018

This just happened to me over the weekend, several times. There was nothing in front me. No car, no overpass, straight lanes of 2 miles of freeway then suddenly the car breaks going from 73 down to 50 or so in a matter of seconds. I tried to accelerate but it wouldn't so I tap the break to disengage and accelerated again.

Whatever the cause, Telsa is going to have a lot of explaining to do if many owners get rear ended due to this flaw. This is dangerous for everyone. Luckily, ever time this happened, there were no cars immediately behind me or they were far away and notice the sudden slow down and reacted.

wiboater4 | 14 maggio 2018

Were there cars in the other lane ? After watching some of those near misses on you tube it showed the car stopping from cars coming from the side to avoid accidents. I'm wondering if someone ahead in another lane maybe came over the line a little or something like that, even far ahead.

laovision | 14 maggio 2018

wiboater4 - There was a car next me to me and it was going straight and I had already passed it. So, there was nothing in front of the car in either lane.

vmulla | 14 maggio 2018

I've experienced this in AP1 (S & X)? and EAP (S & 3)
It happens occasionally, and can be unnerving with someone behind you.
Here's a older post that will give you a context of why this may be happening. The system has evolved a lot since the post, but the challenges addressed are the same. Not all incidents can be explained, because what a human sees and what the system sees are different. But hopefully you'll understand the false positive obstacles detected by the system.

dkabq | 14 maggio 2018

@laovision what was the displayed speed limit on your screen. If it detects a reduction in speed limit it will automatically reduce your speed in autopilot and not allow you to exceed. I have seen this multiple times when approaching turns in the freeway. Did you happen to look at the speed limit registered on the screen even if the speed limit might not have changed according to the freeway signage..

jefjes | 14 maggio 2018

Is it really necessary to manually report this to Tesla since they are collecting data to improve autopilot all the time anyway? I can see that by manually sending a bug report, it may bring more immediate attention to a problem but is it really going to help in these cases? Since I don't have my car yet, I'm asking to clarify and not to criticize because anything that will advance the development of a safer car is a plus IMHO.

vmulla | 14 maggio 2018

When in doubt report. Even if Tesla is aware of a problem from other sources, an additional data point will help.
Software roll outs are planned several months in advance, unless the bug reported is massive Tesla will not drop what they're doing to work on the bug. This is true in any major software shop - triage of bugs and release management is part of normal operations.

vmulla | 14 maggio 2018

To continue from above - I expect Tesla to monitor the forums for bugs, enhancement requests, feedback on changes made.
If a certain thread is gathering attention because of a bug reported here, then I'm hoping someone in Tesla is taking notice and doing their part to fix it.
So I think its important to frame the discussion on these forums.
Example - If its a bug:
Hey, here's something I found, are you experiencing this too (Like this thread)
Hey, here's my observation, but this could be the solution (Preempting negative feedback if you have good info)
Hey, here's my observation, but it only happens in these specific situations (Providing context - very valuable)

martinbogo | 14 maggio 2018

Tesla does not look at these forums. There is no indication that they have posted here in a long, long time.

GAGSTESLA | 14 maggio 2018

I too have had this happen. Usually when I am in a fast track lane and the traffic is much slower to the right of me. Usually on a curve too. It happens so infrequent that it startles the heck out of me when it does. Also, I have freaked a couple people out behind me when it does this. Gotta stay alert, that is for sure.

laovision | 14 maggio 2018

@dkabq I was already driving in the speed set in AP, no over. Then I changed lane and going straight and about 5 seconds later the sudden braking started as though the car saw something in front of it. This behaved more like AEB.

jamilworm | 14 maggio 2018

Not sure if this is what happened, but one possibility is that EAP turned off rather than slamming on the brakes. If that happened, then since your foot isn't on the accelerator the regen braking would kick in and rapidly slow the car.

laovision | 17 maggio 2018

The other weird thing that happened at the same time the car started breaking was the windshield wiper turning on even though I had the auto wipe turned off. There was not rain. This happen both times when I experienced the sudden breaking.

EVRider | 17 maggio 2018

@laovision: Have Service look at your car. Sounds like you might have a problem with the front camera(s) and/or sensor.

@GAGSTESLA: In your case the cause is most likely that your car "thought" one of the cars in the lane next to you was moving over into your lane. That happens to me with AP1 once in a while. The car doesn't always accurately detect the position of lane markers relative to vehicles in front of you, especially on curves.

dfelton | 17 maggio 2018

Had that happened three times already as well (got 1133 miles on the car now). Once I think it was because a shadow of an overhang, and the other two times I don’t know why.... It was not just decelerating, but really slamming the brakes. In all cases nobody was in front of me, and luckily nobody behind me either. Spooky...

gagg370 | 30 giugno 2018

Earlier this week I was driving on interstate 95 at approximately 75mph wile on AP when suddenly without any apparent reason it applied the brakes and reduced the speed of my brand new (400 miles) Model X resulting in a complete loss of confidence of the AP because I could potentially have been tragically rear ended. Contacted Tesla support and after many questions they said they would investigate. What bothers me is that they did not have the honesty to tell me this has happened to many other owners and if they know how to correct the problem

tri_t_to | 1 luglio 2018

This happened to me a few times. Each time it was due to a car passing me on the left lane. I am guessing AP is thinking the car is going to come into my lane so it decided to apply the brakes.

suresh7745 | 27 agosto 2018

happened to me too. sudden slowing, guessing due to strong regen for no apparent reason. it really shook my confidence in EAP. wish i at least understood why. usually in a panic slamming on the acc and no time to look at the screen to see if autopilot detected any false positive.

mlspropertiesllc | 18 settembre 2018

If I'm driving on the freeway at freeway speeds and have a car somewhat close behind, I turn off autopilot as I don't trust it to not suddenly and randomly apply full brakes. 99% of the time it works great but don't trust that 1% on a busy freeway.

terminator9 | 18 settembre 2018

Happens to me almost 90% of the times under this overpass. Only if we had no sun causing shadows.. oh wait then solar energy wouldn't come into play. Then I have seen a few times when a car was on the left or right with no car in the front. I have hopes that the next update will fix it! ;)

kjones | 19 settembre 2018

happened to me several times. 2 overpasses for sure. could the camera be angled wrong?

M3BlueGeorgia | 19 settembre 2018

I keep my foot near the accelerator for occasions like this, and just touching it overrides the braking.
Most of the time you can successfully predict when the car is going to get skittish.

It also rarely happens in traffic, when you are following other cars. Just on the wide open road.

mdelangel2k | 19 settembre 2018

I have had this happen to me as well on 3 occasions. In all 3 there were no cars ahead of me or to either sides. On one, I coming up on an over pass. The other 2 were in teh car pool lane and the only thing that could have triggered it might have been the large diamonds painted on the road. I reported it and tesla tech seem to not find anything in the logs. Waiting to hear back from tech on latest occurrence that happened on 9/16.

tesla | 20 giugno 2019

Having the same problem. It's gotten so bad I'm afraid to use AP. Been submitting bug reports every time it happens.

On 2019.16.2 73d3f3c

r0yster.richardson | 23 giugno 2019

This happens to me enough that I now tend to leave the autopilot off on streets with lots of intersections, stop lights etc. Just too many false braking events. The worst are the times where someone in the oncoming lane will turn make a left turn but be entirely far enough away that it's safe, but the system slams on brakes like an collision is certain. Very un-nerving. Drives itself like a frightened rabbit. This is with frontal collision set to 'Late'.